At the time of Kennedy's presidency no one was still very nice to the Africans. The time of the Civil Rights movement was about to be at its peak and when when Kennedy did this speech he said it as in a way to say, "Hey, no matter what heritage you belong to or what your skin tone is, we should all be friendly to each other and help each other out." That was his way of asking for equality and the peace for the Africans. He wanted them to have the same rights as the white men had at the time. "Without regard to his race or color" meant that everyone that was different should still be together and not worry about that because it did not matter as long as they all agreed in a uniform idea that would be the best for the country and its people.
The poem shows two birds, one of the birds are free and is able to live out in the wild, while the other is caged and is not able to live out in nature. Due to the caged birds suffering it starts to sing to cope with its suffering and to show its wanting for the same freedom the other bird has.
Hope this helped :)
